Stereopticon



(No Model.) 2 Sheets-Sheet 1.

A. MERKT.

STEEEOPTIGON.

Patented Apr. 6, 1897.

ATTORNEYS.

UNITED STATES PATENT OFFICE.

ADOLPII MERKT, OF BROOKLYN, NE YORK.

STEREOPTICON.

SPECIFICATION forming part of Letters Patent No. 580,178, dated April 6,1897.

Application filed March 19, 1896.

To all whom, it Uta/y concern:

Be it known that I, ADOLPH .MERKT, a citizen of the United States,residing in the city of Brooklyn, county of Kings, and State of NewYork, have invented certain new and useful Improvements inStereopticons, of which the following is a specification.

This invention has reference to certain improvements in stereopticons bywhich not only the weight of the same is considerably decreased, but bywhich also the various working parts of the same are capable ofconvenient adjustment, so that the light can be readily kept in thefocus of the lens, new portions of the lime pencil presented to theflame, and various other minor objections to the stereopticonsheretofore in use done away with.

For this purpose the invention consists, first, of a new construction oflight-casing for stereopticons whereby the blackening of the lens duringthe starting of the light is prevented.

The invention consists, secondly, of mechanisms by which the lime pencilcan be readily turned on its axis and adjusted higher or lower, whilethe oXyhydrogen-burner can be adjusted either with the lime pencil orindependen tly therefrom in vertical,longitudinal, and lateraldirections,so that the proper focusing and steadiness of the light areobtained.

The invention consists, further, in certain details of constructionwhich will be fully described hereinafter and finally pointed out in theclaims.

' In the accompanying drawings, Figure 1 represents a side elevation ofmy improved stereopticon. Fig. 2 is aplan view of the operating partsand a horizontal section of the light-casing, taken on line 2 2, Fig. 1,and drawn on a larger scale. Fig. 3 is a vertical longitudinal sectionof the light-casing and the operating parts in the same on line 3 3,Fig. 2; and Fig. 4is a vertical transverse section on line 4: 4, Fig. 3.

Similar letters of reference indicate corresponding parts.

Referring to the drawings, Arepresents the 1ightoasing of my improvedstereopticon, which is made of aluminium, so that its weight isconsiderably reduced. For this purpose the lens-supporting tube A iscast integrally Serial No- 583,903. [No model.)

with the rear wall a of the stereopticon, the front frame a beinglikewise cast of aluminium, while the top and side plates, as well asthe front and side doors, are made of sheetalurninium. The top plate ais provided with curved flanges a at its front and sides, said flangesextending over slotted openings a in the front and side walls, throughwhich the heated air is passed oif to the outside of the casing. Belowthe top plate a of the easin g and riveted thereto is arranged a plate Awhich is parallel with the top plate and provided at its rear edge witha curved flange or, which serves as a guard for the flame when theoxyhydrogen flame is started before the same has developed sufficientheat to bring the lime pencil to incandescence. This starting-flame isusually projected toward the lens, whereby the carbon particles in theflame are condensed and a black film produced on the inner surface ofthe lens, whereby the brightness of the same in transmitting the lightis impaired. This is entirely avoided by the plate A and guard-flange aas by the same the hydrocarbon vapors are thrown in forward directionand carried away from the lens and through the upper front and sideopenings to the outside of the light-casing. The casing is preferablyentirely open at the bottom, so that the air has free access to thelower part of the casing for producing the proper combustion of theoXyhydrogen flame.

By making the light-casing, the lens-tube, and the supporting parts ofthe stereopticon of aluminium the weight of the same is considerablydiminished and the stereopticon thereby better adapted for general useas well as for the use of amateurs, who can thereby carry thestereopticon with greater facility to the place of use.

The light-casing A is supported by means of sleeves d d at its lowerpart on parallel tubular rods 0 O. A dovetailed bridge 0 extendstransversely from one rod O to the other, said bridge serving as asupport on which the different light-giving parts of the stereopticonare supported. On the bridge 0 is guided a slide-piece D, which supportsa square post D. On this post is guided a block D on which are mountedtwo parallel tubular rods E, which are parallel with the longitudinalaxis of the casing, and which are slide on the tubes E. To the spindle fis splined a ratchet-wheel f which is held in position by a keeper fthat is attached to the block e as shown in Fig. 3. The keeper fprevents the ratchet-Wheel f from following the motion of the spindle fin vertical direction, while by the spline connection of theratchet-wheel with the spindle f the latter is compelled to follow theaxial motion imparted to the ratchet-wheel f A springactuated rod f isguided in suitable keepers f on the plate 6 and block D said rod beingprovided with a button at its outer end and a steel pawl f at its innerend, which when its slide-rod is pressed inwardly against the tension ofthe helical spring interposed between its button and the keeper fengages one of the teeth of the ratchet-wheel, so as to turn the same,together with the spindle, on its axis. Simultaneously therewith thespindle is raised by its screw connection with the block e so that thelime pencil is not only turned on its axis, but raised simultaneously bythe action of the pawl-and-ratchet mechanism described. By thisadjustment of the lime pencil a new portion of the same is from time totime acted upon by the oxyhydrogen flame of the burner. This is repeatedfrom time to time,so that thereby notonly new portions of the limepencil are successively pre sented to the flame, but also the formationof deep depressions or cavities on the lime pencil, which graduallyimpair the uniformity of the light, is prevented. The lime pencil isthus gradually and evenly consumed and the injurious heating andbursting of the lens by the heat of the flame thrown on the same whendeep concavities are formed in the pencil entirely avoided. Aforward-and-backward adjustment is imparted to the spindle of the limepencil by means of a screw-rod f provided with a button at its front endand a screw-thread on its rear end, which latter engages aninteriorly-threaded keeperf on the block e so as to produce the shiftingof the block 8 with the spindle f and lime pencil, toward or away fromthe flame. Longitudinal forward-and-backward motion is imparted to thegas supplying tubes E, the burner E, and lime pencil F by a centralscrew-spindle G, which is supported in keepers g at the under side ofthe light-casing A, and which engages a screw-nut g at the under side ofthe bridge 0, so that the same is moved in forward direction with allthe parts supported thereon.

The light-giving parts referred to are also adjusted in lateraldirection by a screw-spindle G, that turns in suitable lugs of thebridge 0 and is adjusted from I the side of the casing, saidscrew-spindle engaging an interiorly-threaded sleeve 9 supported on thebridge, so that thereby the lightgiving parts are readily placed in theproper relative position to the lens.

The means by which the longitudinal and lateral adjustment isaccomplished are well known and were used in stereopticons heretofore,and I therefore do not desire to claim this feature. The new feature,however, to which I desire to call special attention con, sists of thevertical adjustment of the lightgiving parts, by which they can bequickly adjusted by opening the side door and without beinginterferedwith by the heat of the flame at the inside of the light-casing. Thevertical adjustment of the light-giving parts is accomplished in thefollowing manner: The block D by which the gas-supply tubes E aresupported, is provided with a hollow pillar D that is guided on thesquare post D, applied to the slide-piece D. A strong helical spring Dis interposed between the block D and the slide-piece D, on which theentire weight of the gas-supply tubes and the light-giving parts issupported. The upper end 61' of the upright post D is reduced in size,made in round shape, and provided with a screw-thread. A screw-nut D isplaced on the threaded end d and adapted to be raised or lowered, so asto adjust the pillar D and block D on the square portion of the posteither by lowering the same against the tension of the spring D or byraising the same by the action of the spring on reversing the motion ofthe screw-nut, so that thereby the vertical motion of the lightgivingparts is immediately and reliably controlled with but little effort. Bythis arrangement the lightgiving parts are supported on the spring D andreadily adjusted on the upright post D by the joint action of the springD and the adjusting screw-nut D The position of the light-giving partsrelatively to the lens can thus be easily, quickly, and reliablyadjusted in any direction, and likewise the position of the lime penciltoward the flame, so that a bright and uniform light can be kept up. Thefront ends of the gas-supply tubes are connected by flexible tubes withthe gas-cylinders, the front wall of the light-casing being recessed forpermitting the passage of the tubes. The side wall by the upper currentof air, which is deflected by the flanged guard-plate A in forwarddirection, so that the casing is properly ventilated and the heat takenaway from the con- (lensing-lens, whereby the sweating of the latter isprevented. By the improved construction of the casing, as well as thefacility by which the position of the light-giving parts can be adjustedrelatively to the focus of the lens, the light generated is utilized toits full extent for the properillumination of the slidepictures, whichare thrown on the screen in the well-known manner.

Having thus described my invention, I claim as new and desire to secureby Letters Patent 1. Alight-casingforstereopticons,provided with slotsor openings in the sides of its upper part, inwardly-curved,downwardly-extending flanges arranged in front of said openings, and aguard-plate below the top plate provided with a curved guard-flangearranged adjacent to and transversely of the lens-tube for directing theproducts of combustion away from the lens, substantially as set forth.

2. In a stereopticon, the combination with the light-casing, burner, andgas-supply tubes for the burner, of means for vertically adj usting theburner and tubes to which it is attached, consisting of a square postsuitably supported at the bottom part of the casing and having ascrew-threaded upper portion,

a block guided on the squared part of the post and through which saidtubes pass and by which the same are supported, the hollow pillarmounted on said block at one side of the tubes also guided on thesquared part of said post, a cushioning-spring coiled around the squaredpart of the post under the block and acting on said block, and ascrew-nut on the upper part of the post bearing on the upper end of thepillar, substantially as set forth.

3. In a stereopticon, the combination of a lime pencil, a spindle, meansfor supporting the spindle, a ratchet-wheel having a spline connectionwith the spindle, a keeper for pre-

